The HIV epidemic continues to be a significant public health threat in the United States (US), particularly as HIV-positive (HIV+) individuals live longer as a result of improved treatments. However, poor adherence to highly active antiretroviral therapy (HAART) is common, and has a high societal cost in terms of medical expenditures associated with suboptimal adherence. The long-term objective of this proposal by a new investigator is to increase medication adherence among HIV+ individuals in the US. To achieve this, the specific aims are to: 1) conduct formative research on medication adherence and its risk factors among Internet-using HIV+ persons, 2) design a peer support Internet-based HIV medication adherence intervention grounded in the Information-Motivation-Behavioral Skills theory;and 3) pilot the online intervention to assess intervention feasibility and procedures, as well as to obtain population parameters to calculate more precise power and design estimates for a future randomized controlled trial. We propose to develop core intervention components that include user-driven personal profiles that enable participants to communicate with one another and receive peer support, medication self-monitoring and e-mail and text message reminders, and tailored IMB-related feedback that address common problems of adherence. All intervention features will be highly mobile to allow for utilization in contexts in which adherence problems arise. Innovation in this project includes the use of a theoretically-grounded and empirically-derived Internet- based intervention to address HAART adherence, with incorporation of peer interaction and self-monitoring features that have not been widely used in HIV-related online interventions. The PI is experienced in Internet-based HIV-related intervention research, and has assembled a strong multidisciplinary team - representing Epidemiology and Community Health, Psychology, Computer Science, and Pharmacy - to develop the first of its kind intervention. The HIPS Program environment has a national reputation in online HIV prevention studies, and has developed extensive protocols for human subjects'considerations, including data security and cross-validation protocols, which are identified barriers to effective Internet- based research. The significance to HIV treatment adherence research of this proposal includes the development of a comprehensive approach to theoretically-grounded online intervention development and implementation, empirically-based in formative research to understand the risks and needs of Internet-using HIV+ individuals and the use of technology standards for future adherence efforts. The significance of this project to public health involves the development and pilot testing of the first online HAART medication adherence intervention for Internet-using HIV+ individuals that, if successful, can be easily adapted for a more definitive subsequent randomized controlled trial. PUBLIC HEALTH RELEVANCE: The proposed project is to a) conduct formative research on medication adherence and its risk factors among Internet-using HIV-positive individuals and b) design and pilot a theoretically grounded, peer support online HIV medication adherence intervention. The impact of the proposed intervention at the individual level is the reduction of HIV viral load, thereby curtailing progression to AIDS, and at the societal level, by reducing health care costs that result from poor adherence. Using the Internet to deliver the intervention will allow it to be distributed widely and adapted for use with a variety of populations.